The invention is directed to the field of sliding doors, and, more particularly, to an insert for securing to the sash of a sliding panel-type door having rollers to support the door on a rail of a supporting frame.
Sliding panel doors such as patio doors have become extremely popular for use in residential and commercial buildings. This popularity has been achieved as people have sought to have expansive areas open and accessible to the outdoors. Sliding panel doors have become particularly popular in warm climate areas where outdoors activities are enjoyed throughout the year.
Sliding doors are manufactured in a wide variety of styles, ranging from a single moving panel to multiple, parallel panels which ride on adjacent rails. Vertical members of the door panels comprise interlocking parts to reduce air and water infiltration through the door. The doors are conventionally manufactured using aluminum extrusions for framing the glass and mounting the necessary hardware for locking the panels and enabling their lateral movement.
Sliding doors are conventionally supported on a pair of rollers which ride along the rail of a door sill. Some extremely heavy sliding doors require a tandem roller assembly in which a pair of rollers are disposed at each bottom corner of the sash. The rollers are commonly vertically adjustable to raise or lower the door panels to adapt to different installation conditions.
The rollers enable almost effortless lateral movement of the sliding door during its opening and closing. The outer face of the rollers are concave to match the shape of the head of the rail. Only the weight of the doors acting downward on the rail, and contact between the rollers and the head of the rail, maintains the rollers on the rail.
The manufacturers of sliding door units must meet certain structural standards, as well as air and water infiltration standards. These standards are especially important in warmer climate regions which are subject to severe weather conditions such as hurricanes and their accompanying winds and rain. To meet these standards, manufacturers have increased the size and thickness of the framing members of the panels. Although these measures have strengthened the sliding doors, the increased size of the framing members has decreased the aesthetic value of the units.
In addition to the doors requiring adequate strength, it is also essential that the rollers remain on their rails even in high winds, to prevent air and water leakage. A conventional rail has a width of about 0.188", and a conventional roller has an outer diameter of 1.500" and an inner diameter of 1.260". Accordingly, there is a concavity of less than 1/8" (0.120") on the concave face of the rollers and the rollers can be easily dislodged from rails by high winds. In fact, most of the known units fail in testing because the panels are easily dislodged from their rails by high winds, which allows unacceptable levels of air and water leakage past the panels.
Another problem with the known roller systems used in sliding door units is that the rollers provide little security against an intruder simply using a tool to lift the panel off its track to gain access to the property. To prevent such occurrences, sliding door units have incorporated dead bolts and various types of stops to prevent the panels from being moved laterally. Although being of some limited success, these measures have been ineffective in units having two moving panels.
Another protective measure has been to drill aligned holes through the door header and the panel header and insert a dead bolt through the holes to prevent the door from being lifted from the rail. This approach has been unsatisfactory because the dead bolt can be as much as eight feet above the floor and it must be reinserted each time the unit is secured. A further disadvantage of using a dead bolt is that once the panel height is adjusted, the holes in the door and panel headers often become misaligned.